A= 2/2018*2020 + 2021/2020 - 2019/2018
giup em voi
Những câu hỏi liên quan
12 tháng 2 2023 lúc 17:57
So sánh A=\(\dfrac{2018}{2019}\)+\(\dfrac{2019}{2020}\)+\(\dfrac{2020}{2021}\)+\(\dfrac{2021}{2018}\)với 4
Lời giải:
$A=1-\frac{1}{2019}+1-\frac{1}{2020}+1-\frac{1}{2021}+1+\frac{3}{2018}$
$=4+(\frac{1}{2018}-\frac{1}{2019}+\frac{1}{2018}-\frac{1}{2020}+\frac{1}{2018}-\frac{1}{2021})$
$> 4+0+0+0+0=4$
Đúng 2
Bình luận (0)
A=2017/2018+2020/2019
B=2018/2019+2021/2020
So sánh A và B
Xét 2017 /2018 và 2018/2019
1-2017/2018=1/2018
1-2018/2019=1/2019
mà 1/2018>1/2019=>2017/2018<2018/2019
Tương tự có:2020/2019>2021/2020
=>2017/2018+2010/2019<2018/2019+2021/2020
so sánh: 2018^2019+1/2018^2020+1 và 2018^2020+1/2018^2021+1
2018^2019+1/2018^2020+1 bé hơn 2018^2020+1/2018^2021+1
2021/2022 + 2020/2021 + 2019/2020 + 2018/2019 + 2017/2018 rôì so sánh với 5
A = 2021/2022+2020/2021+2019/2020+2018/2019+2017/2018
A<2022/2022+2021/2021+2020/2020+2019/2019+2018/2018
A<1+1+1+1+1
A<5
Đúng 0
Bình luận (0)
So sánh 2018/2019 + 2019/2020 + 2020/2021:3
Bằng nhau
Ht cho mik
2021/2018 x 2022 ... ... ... 2019/2020 x 2020
Bài tập: So Sánh
M= \(\frac{2018}{2019}\)+\(\frac{2019}{2020}\)+\(\frac{2020}{2021}\)
N=\(\frac{2018+2019+2020}{2019+2020+2021}\)
Ta có :
\(N=\frac{2018+2019+2020}{2019+2020+2021}\)
\(=\frac{2018}{2019+2020+2021}+\frac{2019}{2019+2020+2021}+\frac{2020}{2019+2020+2021}\)
Mà \(\frac{2018}{2019}>\frac{2018}{2019+2020+2021}\)
\(\frac{2019}{2020}>\frac{2019}{2019+2020+2021}\)
\(\frac{2020}{2021}>\frac{2020}{2019+2020+2021}\)
\(\Leftrightarrow M>N\)
Đúng 0
Bình luận (0)
Trả lời:
Ta có:
\(\frac{2018}{2019}>\frac{2018}{2019+2020+2021}\)
\(\frac{2019}{2020}>\frac{2019}{2019+2020+2021}\)
\(\frac{2020}{2021}>\frac{2020}{2019+2020+2021}\)
\(\Rightarrow\frac{2018}{2019}+\frac{2019}{2020}+\frac{2020}{2021}>\frac{2018+2019+2020}{2019+2020+2021}\)
hay \(M>N\)
Vậy \(M>N\)
Ta có :
N = \(\frac{2018}{2019+2020+2021}+\frac{2019}{2019+2020+2021}+\frac{2020}{2019+2020+2021}\)
Mà \(\frac{2018}{2019}>\frac{2018}{2019+2020+2021}\)
\(\frac{2019}{2020}>\frac{2019}{2019+2020+2021}\)
\(\frac{2020}{2021}>\frac{2020}{2019+2020+2021}\)
\(\Rightarrow M>N\)
2018^2019+2019^2020+2020^2021 cia 12 dư bao nhiêu ?
cia thành chia nhé
1.Cho A=20172018+20182019+20192020+20202021+2018
a)CMR: A chia hết cho 10
b)CMR 0,7 . A chia hết cho 7
